Fractionating plate



June 27, 1939'. w. A. PETERS. J

FRACTIONATING PLATE Filed July 21, 1937 2 Sheets-Sheet 1 I BY A ATTO R N E S June 27, 1939. PETERS JR 2,164,080

FRACTIONATING PLATE Filed July 21, 1937 2 Sheets-Sheet 2 INVENTOR T5, \x-

, Patented Julie 21, 19391 I "UNITED STATES,

2,164,080 YFRACTIONATING rm'rs William A. Peteraf J r Seattle, Walla, alsignor to E.'B.,Badger 4: Sons 00., Boston. Mala, a corporation oi Massachusetts Application July 21,1'1987, Scrlat No. 154.78!

This invention relates to i'ractionating plates 1 for use in iractionating columns or stills. In

these columns or stills the vapors pass. upwardly from the bottom of the still through reflux liquid s flowing downwardly from the top of the still and across the iractionating plates.

Fractionating plates, such as are commonly in use, are fltted with chimneys and bubble caps. The vapors passing upwardly through the tower it) are deflected by the bubble caps at each plate and caused to bubble through the liquid on the plate. Usually the plates are flat and of an area substantially as great as the cross-sectional area of the column. These plates therefore present 16 elongated outer edges which must be'machined to flt'them accurately in the column and-to produce substantially liquid tight joints for preventing leakage oi the liquid from one plate to am other. The machining operations required in 20 the production oi'the plates are expensive. thereby greatly increasing the cost 0! the fraction ating towers.

- The principal object of this invention is to produce iractionating plates consisting of a plu- 25 rality of small units which may be easily assembled to form a plate satisfactory from the standpoint of preventing leakage-oi liquid without machining and eflicient as to the contacting oi the vapor and reflux liquid.

A further object 01' the invention is to produce tractionating plates in which the vapor passages are disposed below the normal level of the liquid on the fractionating plates but above the upper surface 0! the plate.

v 35 In the former the invention illustrated, a

. iractionating plate assembly may consist of a pan to which liquid is delivered having supporting elements thereacross upon which are seated a plurality of plate members provided with up- 40 standing rims which project above the surface oi the pan but below the normal level of the liquid on the pan. Bubble caps with dd'wnwardly depending side flanges straddle the adjacent rims 01 adjacent plate members to direct the vapors 45 through the liquid on the plate. The bubble caps are provided with bubble slots or apertures which are disposed below-the tops'oi. the rims oi the plate members, therebycausing the vapors to bubble through the'liquid on theplate and to 50 build up a slight pressure to reduce the level of theliquld within the bubble. caps. Comparatively. narrowsupporting flanges are provided on the plate members which abut or overlie similar flanges on adjacent plate members. The

55 flanges are so proportioned and may be so supported that they form a substantially liquid tight Joint without being machined.

This construction has the advantage. that a plurality oi the plate members and bubble caps may be readily assembled to producei'ractionating plates 01' any desired size which willefllciently handle the reflux liquid without-leakage.

For a better understanding oi the presentinvention, reference may be had'to the accompanying drawings in which:

Figure 1 is a plan view partly broken of a iractionating plate embodying one form of the invention;

Figure 2 is an enlarged broken;

Figure 3 is an enlarged cross-sectional .view taken on line 3-3 of Figure 2; i

Figure 4 is a broken perspectiveview 0! one of the plate members;

Figure 5 is a broken perspective view of one plan view partly of the bubble-caps; and

Figure 6 is a sectional view taken on line'I-B of Figure 2.

In the form oi. the invention illustrated, the. fractionating plate consists of a circular pan Ill of any desired size having an upstanding rim I I2 and a dam ll thereacross overvwhich reflux liquid flows from the down flow pipes II. The

--ends of the pipes it are disposed below the tops of the dam l4 thereby creating a liquid seal and to preventing passage oi. .vapor up the pipes. A

similar darn ll of the same or lesser height is provided on the opposite side 0! the pan over which the reflux liquid flows to down spouts It for delivery to the next lower iractionating' plate. The height of dam ll controls the level 01' the liquid on the plates. The pan I0 is pro- ,vided with a substantially square center aperture I8 which is divided by a T-beam 20 supporting the plate members 22. It will be under- 40 stood that, the shape and size 01' the pan l0 can be varied, as desired, as-well as the shape and size of the aperture il. Likewise, the T-be'am may be eliminated in smaller plates or a plurality of them maybe used in larger plates. Each plate member 22 consists of a troughshaped casting having narrow flat flanges 24 extending from opposite ends of the members and laterally beyond their side walls 28. As illustrated the plate members 22 may be race tangular but, if desired maybe 01' any shape suitable'to flt in the pan II. The side walls II project above the upper surface of; the flanges Micrafptirpose to be, described.

Tneplate members "are placed inthe" aw, ll

ture I! of the pan III with flanges 24 resting on the T-beam 20, and on the pan adjacent the manner of support, act with the adjacent flanges I to give substantially liquid tight joints.

The vapor passages between the side walls 26 of adjacent plate members 22 are covered by-bubble caps consisting of inverted trough-like rectangular members 28 having narrow end walls 30 andsidewalls 32, the lower edges of which rest on the bottoms of .the'plate members 22. The side walls 32 are of suflicient height so that the inner portion of the bubble cap remains spaced above-the. walls 26 of the plate members. The narrow end walls '30 seat tightly against the upper surfaces of the flanges 24 to prevent leakage of' liquid at these points. The bubble caps 28 and plate members 22 may be connected and retained in tight engagement by any suitable means, such asbolts 34 having enlarged heads engaging thebases of adjacent plate members and passing through the bubble caps.

The side walls 32 of the bubble caps are slotted to provide passages 36 through which the vapors pass, the slots terminating below the level of the side walls 26. This arrangement of the bubble caps maintains the level of the liquid enclosed therein at a lesser height than the level of the reflux. liquid on the plate. The pressure of the vapor is sufllcient to displace the liquid to a level below the tops of walls 26. At the same time the gases are forced to bubble through and are washed by'the liquid externally of the caps since the upper edges of the bubble slots are below the tops of walls 26 and the level of the reflux liquid on the plate.

- The above described construction presents the advantage that the film of liquid flowing across the iractionating plate cannot leak over the side walls 26 of the plate members 22 within the bubble caps 28.

The joints formed by the flanges 24 and their supporting elements are sufficient to retain the liquid on the plates for the pressure of the vapor below the plate overcomes any tendency of liquid to seep through the joints. It should be noted that the joints are sufliciently elevated so that the -liquid head which the vapors must overcome is minimized. Thus any leakage through the joints will be the upward flow. of vapor and not the downward flow of liquid.

. The outermost plate members 22 are maintained in sealing-relation to the pan ill by means of plates 38 having their upper surfaces disposed on the level of dam ll or above the normal liquid level on theplate and having a downwardly directed flangelli extending from dam I 4 to dam l4 cooperating the plate members 22 and the supporting members to form a liquid seal.

' It will be understood that the principles of this invention can be embodied in many different shapes and sizes of the device and that the plate members and bubble caps may be supported in the pan in any desired manner without departing from the invention. The device described should therefore be considered illustrative only, and not as limiting the scope of the claims.

I claim: v

1. In a fractionating plate the-combination of a supporting pan, a plurality ot'plate' members having side walls and end walls, narrow end flanges on said plate members adjacent the upper edges of the end walls and engaging the supporting pan and similar flanges on adjacent plate members, the side walls on adjacent plate members being spaced apart to form vapor passages, bubble caps straddling the passages and extending downwardly between the side walls of adjacent plate members and bubble slots having upper edges disposed below the upper edges of theslde walls whereby the joints formed by the flanges and supporting pan are adjacent the surface oi liquid on the pan and the bubble slots are disposed substantially entirely below the joints.

2. In a fractionating plate, the combination of a plate member comprising a base, end walls on the base, side walls on the base of greater height than the end walls and supporting flanges projecting outwardly from adjacent the upper edges of the end walls and extending laterally beyond the side walls whereby the plate. members may be suspended by the flanges substantially entirely below a supporting structure and the joints formed by the flanges and the supporting structure will be above the major portion of the plate member.

3. In a iractionating plate, the combination of a supporting member having liquid level regulating means thereon, a-plurality of separate troughshaped plate members, flanges on the plate members adjacent their upper edges engaging the supporting member inproximity to the surface of the liquid to suspend the plate members substantially entirely below the supporting member and in spaced relation to provide vapor passages, and bubble caps straddling the vapor passages andhaving apertures therein disposed within the plate members whereby the joints formed by engagement of the flanges with the supporting member will be subjected to sufilcient vapor pressure from below to overcome the hydrostatic pressure of liquid and the leakage of liquid through the joints will be prevented.

4. In a iraction'ating plate, the combination of supporting means, trough-shaped plate mem bers supported on and depending below said supporting means whereby crevices or joints between the members and the supporting means are substantially. in the plane of the supporting means and adjacent the surface of liquid on theiractionating'plate, and bubble caps cooperating with the plate members and having bubble apertures disposed within the plate members and sub stantially entirely beneath the crevices or joints.

WILLIAM A. PETERS, JR. 

